Rotary Tree Felling Frame for Stable Forward Fall Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The self-propelled tree felling and transporting machine described in Patent Literature 1 faces instability in the felling direction of a cut standing tree due to the fulcrum effect, leading to potential unintentional felling directions and lifting of the machine, necessitating a larger and heavier design to maintain stability.
Innovation Solution
A felling work vehicle with a rotary frame and grapple device that allows the standing tree to be grasped and cut at a lower position, then rotated about a forward axis to ensure stable felling, incorporating features like a rotary arm, universal support mechanism, and torque application to control the felling direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the grapple device holds the standing tree from the sides and the cutting device cuts the tree from the side, then the tree can be felled, but the felling direction becomes unstable due to the fulcrum effect causing the tree to contact the stump unintentionally
Solution Approach 1:
Instead of cutting the tree from the side and allowing it to fall naturally, the invention inverts the approach by positioning the cutting device to cut the tree from the rear end (opposite to the grapple holding position). This inversion ensures that when the tree is felled, the front end falls first and the rear end follows, preventing the rear end from contacting the stump and causing unstable felling direction. The rotation frame rotates in the opposite direction compared to conventional designs, achieving stable felling control.
2Stability of the object's composition
If the machine is designed with certain size and mass to suppress lifting during felling, then lifting is prevented, but the size and weight of the machine increase
Solution Approach 1:
The invention applies preliminary action by positioning the rotation axis forward of the standing tree before felling begins. This forward positioning of the rotation axis creates a lever arm that generates a downward force on the machine body during the felling rotation, counteracting the lifting force before it can cause instability. By pre-configuring the rotation axis position, the machine prevents lifting without requiring increased mass or size.
3Stability of the object's composition
If the rotation axis is positioned forward of the standing tree, then the cut tree is lifted and felled stably toward the front, but the machine structure becomes more complex
Solution Approach 1:
The rotation frame is designed with multi-functionality, serving both as the structural support for the grapple device and cutting device, and as the rotating mechanism that controls felling direction. By making the rotation frame universal, the invention avoids adding separate complex structures for rotation support, thereby achieving stable felling direction control without proportionally increasing overall device complexity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention is a felling work vehicle (1) including: a vehicle body (2); traveling devices (4); a rotary frame (6) disposed between these traveling devices, and having a recessed portion (6a) that receives, a standing tree; a grapple device (8) coupled to the rotary frame, and including grapples configured to hold the standing tree, which is received in the recessed portion of the rotary frame; and a cutting device (12) configured to cut the standing tree, at a position lower than the grapples, wherein the rotary frame is attached to the vehicle body so as to be rotatable about a rotation axis (6b), the rotation axis being positioned to be located forward of the standing tree, which is held by the grapple device, with respect to the vehicle body, and the standing tree is felled toward the front of the vehicle body by rotating the rotary frame.